Your ancestry’s influence on your earwax and armpits
How familiar are you with your grandmother’s earwax? Probably more than you’d (like to) think, since there’s a very high chance that your ear-goo closely resembles hers, as well as her grandmothers, and hers before her. This is because of the two types of earwax humans produce, it all comes down to a single gene to determine which kind of wax your ears will make. Before you start diving into your ears to for evidence of that single extra guanine in your genome, keep in mind that your earwax is supposed to be in your ears, and may even be helping to keep you healthy. Or it might not…
Earwax is technically known as cerumen, and is basically a mix of oil, sweat and dead hair and skin debris that sits on the outer edge of your ear canal. It may be there to help keep skin moistened, act as a trap for bugs considering spelunking in your ear, or may even help kill bacteria. Various studies have found that earwax can both kill or promote bacterial growth, depending on the wax involved. Dry wax seems to fend off bacteria, while the stickier stuff may actually feed strains like E. coli.
Which wax for you?
The type of earwax you have is up to your genes. People with African or European ancestry are more likely to have darker, stickier and smellier earwax, while people of Asian descent are more likely to have the pale, flakier version in their ears. While only a single base-pair is changed between the two groups, differences in wax has been relied upon to help trace migration routes of ancient peoples. The gene that actually flips this sticky/flaky-switch, called ABCC11, is also tied to armpit secretions, with owners of sticky earwax also producing more of a protein in their pits that feed stinky bacteria. So smellier armpits likely come with more odorous ears, although you really shouldn’t try sticking any deodorant in your ears, because you really shouldn’t be sticking anything in there.
No poking or prodding
By this point, you may be wanting to grab some cotton swabs to sample your personal wax supply, but resist the urge because it’s potentially dangerous to stick anything in your ear canal. You may accidentally crush wax further into the canal, building up pressure and limiting your hearing. Even worse, small pointy things can puncture your ear drum, which will absolutely be worse than a bit of waxy crud in your ear. If you’re really concerned about how much wax you’re carrying in your head, doctors have ways to soften and lubricate wax to allow it to drain safely, but odds are this isn’t necessary for most people. Whatever you do, don’t do any kind of “ear candling,” which supposedly cooks and wicks the wax out of your head, but value-wise is the equivalent of a wax leeching to balance your ear’s humors.
Remember, if you really need to know about your wax and are unsure about your ancestry, it’s probably safe to just go ask your grandparents.
Source: The mysterious properties of the wax in your ear by Jason G Goldman, BBC Future